Flange fitting with leak sensor port

ABSTRACT

A leak detection feature for a fluid conduit. The leak detection feature facilitates the monitoring of fluid leaks at the interface of two adjoining conduit flange fittings. An embodiment of a flange fitting with a leak detection feature for a fluid conduit having an opening. The flange fitting includes a flange body around the opening of the fluid conduit, a leak detection passageway formed in the flange body, and a leak detection port formed in the flange body. The flange body has a sealing face surface configured to mate with a cooperating flange fitting, and the leak detection passageway terminates at the sealing face surface. The leak detection port is in fluid communication with the leak detection passageway, and the leak detection port is configured for fluid communication with a leak sensing apparatus.

CROSS-REFERENCE TO RELATED APPLICATIONS

The subject matter described herein is related to the subject matterdisclosed in the following applications, the relevant content of whichis incorporated by reference herein: United States Patent ApplicationPublication number 2005/0120534 A1, titled Shrouded Fluid-ConductingApparatus; United States Patent Application Publication number2006/0278017 A1, titled Shrouded Body Flow Meter Assembly; United StatesPatent Application Publication number 2006/0278760 A1, titled Fittingswith Redundant Seals for Aircraft Fuel Lines, Fuel Tanks, and OtherSystems; United States Patent Application Publication number2006/0278761 A1, titled Aerial Refueling System; United States PatentApplication Publication number 2006/0278763 A1, titled AdjustableFittings for Attaching Support Members to Fluid Conduits, IncludingAircraft Fuel Conduits, and Associated Systems and Methods; UnitedStates Patent Application Publication number 2007/0051406 A1, titledShrouded Valve Apparatus and Related Methods; United States PatentApplication Publication number 2009/0091126 A1, titled Shrouded CouplingAssemblies for Conduits; and United States Patent ApplicationPublication number 2009/0102187 A1, titled Boot Shrouds for Joints inConduits.

TECHNICAL FIELD

Embodiments of the subject matter described herein relate generally tofluid conducting apparatus and systems. More particularly, embodimentsof the subject matter relate to leak detection features and technologiessuitable for use with fluid conducting apparatus and systems.

BACKGROUND

It is sometimes necessary to couple together fluid (gas and/or liquid)conduits. For example, aircraft employ fuel conduits to transfer fuelfrom a source to a receiving vessel. The Federal Aviation Administration(FAA) has promulgated regulations regarding the safe transfer of fuelvia conduits in the aerospace industry. In order to meet some of theseregulations, fuel transfer conduits may be structured as a “tube withina tube,” often referred to as a “shrouded conduit,” which effectivelyprovides a double-walled conduit for containment of the fuel. In use,the fuel flows in the inner tube, or primary fuel conduit, and theannular space between the inner and outer conduits provides a leakdetection zone. This annular space may also be used to carry other fluidconcurrently with the fuel.

Leak detection at a junction or flange between two conduits is oftenimportant, especially when the fluid in the conduits is combustible,highly valuable, or a toxic or hazardous substance. Accordingly,technologies for leak prevention and detection of leaks at a junctionbetween two conduits are important in certain industries and in certainfluid transfer operations.

BRIEF SUMMARY

A flange fitting for a fluid conduit as provided herein includes a leakdetection feature that can be used to monitor for leakage at the flangefitting interface. The leak detection architecture employs a (nominally)sealed leak detection passageway that resides between the two opposingflange faces. The leak detection passageway receives and transportsleaked fluid to an external leak sensing apparatus. In this manner, theinterface between sections of the conduit can be easily monitored forthe presence of leaks.

The above and other aspects may be carried out by an embodiment of aflange fitting having a leak detection feature for a fluid conduithaving an opening. The flange fitting includes a flange body around theopening of the fluid conduit, the flange body having a sealing facesurface configured to mate with a cooperating flange fitting, a leakdetection passageway formed in the flange body, the leak detectionpassageway terminating at the sealing face surface, and a leak detectionport formed in the flange body, the leak detection port in fluidcommunication with the leak detection passageway, and the leak detectionport being configured for fluid communication with a leak sensingapparatus.

The above and other features may be found in an embodiment of a flangefitting with a leak detection feature for an inner fluid conduit and anouter fluid conduit surrounding the inner fluid conduit. The flangefitting includes: a flange body having an inner portion around anopening of the inner fluid conduit, and having an outer portion aroundan opening of the outer fluid conduit, the flange body having a sealingface surface configured to mate with a cooperating flange fitting; aninner leak detection passageway formed in the inner portion of theflange body, the inner leak detection passageway terminating at thesealing face surface; and an inner leak detection port formed in theinner portion of the flange body, the inner leak detection port in fluidcommunication with the inner leak detection passageway, and the innerleak detection port being configured for fluid communication with a leaksensing apparatus.

The above and other features may be implemented in an embodiment of aflange fitting assembly with a leak detection feature. The flangefitting assembly includes a first flange fitting for a fluid conduit anda second flange fitting for the fluid conduit, where the flange fittingsare configured to mate with one another. The first flange fittingincludes a first flange body around the opening of the fluid conduit,the first flange body having a first sealing face surface, a first leakdetection passageway formed in the first flange body, the first leakdetection passageway terminating at the first sealing face surface, anda first leak detection port formed in the first flange body, the firstleak detection port in fluid communication with the first leak detectionpassageway. The first leak detection port is configured for fluidcommunication with a leak sensing apparatus. The second flange fittingincludes a second flange body around the opening of the fluid conduit,the second flange body having a second sealing face surface configuredto mate with the first sealing face surface, a second leak detectionpassageway formed in the second flange body, the second leak detectionpassageway terminating at the second sealing face surface, and a secondleak detection port formed in the second flange body, the second leakdetection port in fluid communication with the second leak detectionpassageway, and the second leak detection port being configured forfluid communication with the leak sensing apparatus. The first leakdetection passageway and the second leak detection passageway combine toform a leak detection duct when the first flange fitting and the secondflange fitting are coupled together.

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the detaileddescription. This summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the subject matter may be derived byreferring to the detailed description and claims when considered inconjunction with the following figures, wherein like reference numbersrefer to similar elements throughout the figures.

FIG. 1 is a perspective view of an embodiment of a single walled conduitsection;

FIG. 2 is a perspective view of a detailed portion of the conduitsection shown in FIG. 1;

FIG. 3 is a perspective view of the detailed portion of the conduitsection shown in FIG. 2, as viewed toward the back side of the flangefitting;

FIG. 4 is an end elevation view of the detailed portion of the conduitsection shown in FIG. 2;

FIG. 5 is a cross sectional view of two single walled conduit sectionscoupled together by an embodiment of a flange fitting assembly;

FIG. 6 is a perspective cross sectional view of the two conduit sectionsshown in FIG. 5;

FIG. 7 is a perspective view of the flange fitting shown in FIGS. 1-4,as viewed from the back side;

FIG. 8 is a perspective face view of the flange fitting depicted at theright side of FIG. 1;

FIG. 9 is a perspective view of an embodiment of a double walled conduitsection;

FIG. 10 is a perspective view of a detailed portion of the conduitsection shown in FIG. 9;

FIG. 11 is an end elevation view of the detailed portion of the conduitsection shown in FIG. 10;

FIG. 12 is a cross sectional view of two double walled conduit sectionscoupled together by an embodiment of a flange fitting assembly;

FIG. 13 is a perspective cross sectional view of the two conduitsections shown in FIG. 12;

FIG. 14 is a perspective view of the flange fitting shown in FIGS. 9-11,as viewed from the back side;

FIG. 15 is a perspective face view of the flange fitting depicted at theright side of FIG. 9; and

FIG. 16 is a schematic representation of an embodiment of a leakdetection system.

DETAILED DESCRIPTION

The following detailed description is merely illustrative in nature andis not intended to limit the described embodiments or the applicationand uses of such embodiments. As used herein, the word “exemplary” means“serving as an example, instance, or illustration.” Any implementationdescribed herein as exemplary is not necessarily to be construed aspreferred or advantageous over other implementations. Furthermore, thereis no intention to be bound by any expressed or implied theory presentedin the preceding technical field, background, brief summary or thefollowing detailed description.

The following description may refer to elements or nodes or featuresbeing “connected” or “coupled” together. As used herein, unlessexpressly stated otherwise, “connected” means that oneelement/node/feature is directly joined to (or directly communicateswith) another element/node/feature, and not necessarily mechanically.Likewise, unless expressly stated otherwise, “coupled” means that oneelement/node/feature is directly or indirectly joined to (or directly orindirectly communicates with) another element/node/feature, and notnecessarily mechanically.

In addition, certain terminology may also be used in the followingdescription for the purpose of reference only, and thus are not intendedto be limiting. For example, terms such as “upper,” “lower,” “above,”and “below” refer to directions in the drawings to which reference ismade. Terms such as “front,” “back,” “rear,” “side,” “outboard,” and“inboard” describe the orientation and/or location of portions of thecomponent within a consistent but arbitrary frame of reference which ismade clear by reference to the text and the associated drawingsdescribing the component under discussion. Such terminology may includethe words specifically mentioned above, derivatives thereof, and wordsof similar import. Similarly, the terms “first,” “second,” and othersuch numerical terms referring to structures do not imply a sequence ororder unless clearly indicated by the context.

The subject matter described herein is related to the subject matterdisclosed in the following documents, the relevant content of which isincorporated by reference herein: U.S. Pat. No. 6,848,720, titledShrouded Fluid-Conducting Apparatus; U.S. Pat. No. 7,213,787, titledValves for Annular Conduits Including Aircraft Fuel Conduits andAssociated Systems and Methods; U.S. Pat. No. 7,293,741, titled Systemand Methods for Distributing Loads from Fluid Conduits, IncludingAircraft Fuel Conduits; United States Patent Application Publicationnumber 2005/0120534 A1, titled Shrouded Fluid-Conducting Apparatus;United States Patent Application Publication number 2006/0278017 A1,titled Shrouded Body Flow Meter Assembly; United States PatentApplication Publication number 2006/0278760 A1, titled Fittings withRedundant Seals for Aircraft Fuel Lines, Fuel Tanks, and Other Systems;United States Patent Application Publication number 2006/0278761 A1,titled Aerial Refueling System; United States Patent ApplicationPublication number 2006/0278763 A1, titled Adjustable Fittings forAttaching Support Members to Fluid Conduits, Including Aircraft FuelConduits, and Associated Systems and Methods; United States PatentApplication Publication number 2007/0051406 A1, titled Shrouded ValveApparatus and Related Methods; United States Patent ApplicationPublication number 2009/00911266 A1, titled Shrouded Coupling Assembliesfor Conduits; and United States Patent Application Publication number2009/0102187 A1, titled Boot Shrouds for Joints in Conduits.

FIG. 1 is a perspective view of an embodiment of a single walled conduitsection 100 having a leak detection feature integrated therein. FIG. 2is a perspective front view of a detailed portion of conduit section100, FIG. 3 is a perspective rear view of the detailed portion ofconduit section 100, and FIG. 4 is an end elevation view of the detailedportion of conduit section 100. FIG. 5 is a cross sectional view of twosingle walled conduit sections coupled together by an embodiment of aflange fitting assembly, and FIG. 6 is a perspective cross sectionalview of the two conduit sections shown in FIG. 5. In addition, FIG. 7 isa perspective view of the flange fitting shown in FIGS. 1-4, as viewedfrom the back side, and FIG. 8 is a perspective face view of the flangefitting depicted at the right side of FIG. 1.

Conduit section 100 is suitably configured to carry any of a wide rangeof fluids (such as gases, liquids, or any flowing substance), regardlessof whether the fluid is being used as a fuel. Accordingly, specificreferences to fuel, gases, or liquids herein should not be construed aslimiting the scope of the described embodiments.

Conduit section 100 generally includes, without limitation: a fluidconduit 102 having a first end 104 and a second end 106; a first flangefitting 108 at first end 104; a second flange fitting 110 at second end106; and a leakage collection conduit 112. First flange fitting 108 iscoupled to (or is integrally formed with) first end 104 of conduitsection 100 such that the respective opening 113 of conduit section 100terminates at first flange fitting 108. Likewise, second flange fitting110 is coupled to (or is integrally formed with) second end 106 ofconduit section 100 such that the respective opening of conduit section100 terminates at second flange fitting 110. First flange fitting 108and second flange fitting 110 are suitably configured such that conduitsection 100 can be coupled to additional conduit sections havingcompatible flange fittings that mate with first flange fitting 108 orsecond flange fitting 110. Alternatively, conduit section 100 may beconnected by way of first flange fitting 108 and/or second flangefitting 110 to any one of a wide range of other fluid-conductingapparatus having compatible end fittings. In alternate embodiments,flange fitting 108 or flange fitting 110 can be replaced with an endcapor other component that serves to seal or cap an end of conduit section100.

Fluid conduit 102, first flange fitting 108, and second flange fitting110 are formed from a strong and fluid impermeable material that isresistant to the intended fluid to be transported, such as, withoutlimitation: aluminum (e.g., 6061-T4 aluminum); stainless steel; plastic;a composite construction; or the like. In this regard, first flangefitting 108 and second flange fitting 110 can be welded onto fluidconduit 102 to form conduit section 100. Although the illustratedembodiments include generally cylindrical fluid conduits, otherembodiments may employ conduits having different cross sectional shapesand configurations, such as rectangular, square, or elliptical conduits.

FIG. 5 is a side view of a cross section taken through the longitudinalaxis of the conduits, and through a leak detection port 124 (describedbelow). FIG. 6 is a perspective view of the same cross section. Firstflange fitting 108 and second flange fitting 110 are suitably configuredto mate with each other such that, when two compatible conduit sectionsare coupled together, a fluid tight seal is formed between first flangefitting 108 and second flange fitting 110. Ideally, this fluid tightseal prevents the fluid carried by fluid conduit 102 from leakingoutside fluid conduit 102. For this particular embodiment, first flangefitting 108 and second flange fitting 110 are not identical components.Although not a requirement in all embodiments, first flange fitting 108is designed to be a seal-retaining component, while second flangefitting 110 is designed to be a seal-cooperating component, as describedin more detail below.

Referring to FIGS. 2-4, first flange fitting 108 generally includes aflange body 114 having a number of features and elements formed therein.Flange body 114 represents the main portion of first flange fitting 108,and flange body 114 resides around the opening 113 of fluid conduit 102.In this embodiment, flange body 114 surrounds and completely encirclesthe opening 113, as shown in the figures. Flange body 114 includes agenerally defined sealing face surface 116 (see FIG. 5) that correspondsto a common plane shared by certain prominent features of first flangefitting 108. Sealing face surface 116 cooperates and mates with therespective sealing face surface of the adjoining flange fitting.

As mentioned previously, flange body 114 includes a number of featuresand elements formed therein. These features include, without limitation:an outer seal groove 118; a leak detection passageway 120; an inner sealgroove 122; and a leak detection port 124 (depicted in cross section inFIG. 5). Due to the cylindrical form of this embodiment of fluid conduit102, outer seal groove 118 is a ring shaped channel that encircles theopening 113 of fluid conduit 102. Outer seal groove 118 is suitablysized and shaped to accommodate a seal, sealing compound, a ring seal, agasket, or the like. For this embodiment, outer seal groove 118 receivesand retains an outer ring seal 126 as depicted in FIG. 5, positionedaround the opening 113. When deployed in this manner, outer ring seal126 remains positioned around the opening 113 of fluid conduit 102. Whenthe two flange fittings are coupled together as shown in FIG. 5, outerring seal 126 gets compressed within outer seal groove 118, forming afluid tight seal between the flange fittings. Inner seal groove 122 issimilarly configured to accommodate a seal, sealing compound, a ringseal, a gasket, or the like. For this embodiment, inner seal groove 122receives and retains an inner ring seal 128 as shown in FIG. 5,positioned around the opening 113. When deployed in this manner, innerring seal 128 remains positioned around the opening 113 of fluid conduit102, and it remains located between fluid conduit 102 and leak detectionpassageway 120. Moreover, outer ring seal 126 remains located aroundinner ring seal 128. As best shown in FIG. 4, a relatively thincylindrical wall of material separates inner seal groove 122 from theinterior space within fluid conduit 102.

Leak detection passageway 120, which terminates at sealing face surface116, resides between outer seal groove 118 and inner seal groove 122. Asbest depicted in FIG. 4, relatively thin cylindrical walls of materialseparate outer seal groove 118 and inner seal groove 122 from leakdetection passageway 120. Due to the cylindrical form of this embodimentof fluid conduit 102, leak detection passageway 120 is realized as aring shaped channel that encircles the opening 113 of fluid conduit 102.In this regard, outer seal groove 118, leak detection passageway 120,and inner seal groove 122 are formed within flange body 114 as threegenerally concentric ringed grooves.

For this embodiment, outer ring seal 126 and inner ring seal 128cooperate to seal leak detection passageway 120 between sealing facesurface 116 and the cooperating flange fitting. Moreover, inner sealring 128 is suitably configured to nominally seal leak detectionpassageway 120 from fluid conduit 102. As used here, “nominally seal”means that under normal and intended operating conditions an actualfluid seal is maintained to at least the minimum specifications. Thus,although a seal might be configured to “nominally seal” something, underunexpected or unusual circumstances that seal might not maintain a truesealed condition. For example, such a nominal seal might be broken ifthe pressure of the fluid contained in fluid conduit 102 exceeds theintended design limits, if the cooperating flange fittings are notadequately coupled together, or the like.

Leak detection port 124 is arranged such that it is in fluidcommunication with leak detection passageway 120. As described in moredetail below, leak detection port 124 is suitably configured for fluidcommunication with a leak sensing/detecting apparatus or system.Referring to FIG. 2, FIG. 4, and FIG. 5, this embodiment of leakdetection port 124 terminates at leak detection passageway 120.Moreover, referring to FIG. 5, leak detection port 124 provides a fluidpath between leak detection passageway 120 and the back surface 130 offlange body 114 (where back surface 130 is opposite sealing face surface116 of flange body 114). As shown in FIG. 5, leak detection port 124 maybe realized as a hole drilled or milled through flange body 114 in adirection approximately perpendicular to the plane defined by sealingface surface 116. This particular embodiment utilizes only one leakdetection port 124 for leak detection passageway 120; any number of leakdetection ports can be used in alternate embodiments.

FIG. 7 is a perspective view of flange fitting 108, as viewed from itsback side, i.e., the side opposite the front or end side. For clarity,FIG. 7 does not show the fluid conduit that would normally be attachedto flange fitting 108. As described above, leak detection port 124 ispreferably arranged to be in fluid communication with a leak sensingapparatus or system (not shown). Accordingly, flange body 114 mayinclude an outlet 132 for leak detection port 124. Outlet 132 can besuitably configured to receive leakage collection conduit 112. Forexample, outlet 132 may represent a threaded hole, a fitting, a holesized to accommodate a press fit with leakage detection conduit 112, aconnector, or the like. Outlet 132 facilitates coupling of leakagecollection conduit 112 to leak detection port 124. In turn, anappropriate leak detector, sensor, system, or apparatus can be coupledto leakage collection conduit 112 for purposes of sensing fluid leakageinto leak detection passageway 120 and/or into leakage detection port124.

As mentioned above, second flange fitting 110 need not be identical tofirst flange fitting 108. In this particular embodiment, second flangefitting 110 mates with first flange fitting 108, and second flangefitting 110 cooperates with the seals of first flange fitting 108. Forease of description, FIG. 8 is a perspective face view of second flangefitting 110, shown without fluid conduit 102. The back side of secondflange fitting 110 is similar to that depicted in FIG. 7, and as such itwill not be redundantly described here. Second flange fitting 110includes a flange body 134 having a sealing face surface 136 that isconfigured to mate with a cooperating flange fitting (such as one havingthe characteristics of first flange fitting 108).

Unlike first flange fitting 108, second flange fitting 110 need not haveany seal grooves formed therein. Rather, sealing face surface 136 itselfserves as a cooperating surface that contacts and compresses the sealsof the cooperating flange fitting. FIG. 5 and FIG. 6 illustrate thisfeature. In this embodiment, second flange fitting 110 includes a leakdetection passageway 138 and a leak detection port 140 formed therein.Leak detection passageway 138 and leak detection port 140 are similar totheir respective counterparts described above for first flange fitting108. Notably, leak detection passageway 138 is preferably shaped, sized,and configured such that it aligns with the leak detection passageway inthe cooperating flange fitting when the two flange fittings areconnected together (as shown in FIG. 5 and FIG. 6). Indeed, the twoopposing leak detection passageways cooperate and combine to form a leakdetection duct when the two flange fittings are coupled together.Consequently, leak detection port 140 is maintained in fluidcommunication with the leak detection passageway and with the leakdetection port of the cooperating flange fitting.

Referring again to FIG. 5 and FIG. 6, the leak detection duct formed bythe two opposing leak detection passageways is sealed between thesealing face surfaces of the two flange fittings. Moreover, the ringseals function to nominally isolate the leak detection duct from theinterior of the fluid conduit. Thus, the leak detection duct ideallyremains void of the fluid passing through the fluid conduit absent aleak condition.

Referring back to FIG. 1, this particular embodiment of leakagecollection conduit 112 spans the length of fluid conduit 102 betweenfirst flange fitting 108 and second flange fitting 110. Thus, one end ofleakage collection conduit 112 is coupled to the leak detection port offirst flange fitting 108, and the other end of leakage collectionconduit 112 is coupled to the leak detection port of second flangefitting 110. The T-shaped fitting 142 of leakage collection conduit 112can be utilized as a coupling point for additional conduit, hoses,pipes, or tubes, which in turn can be routed to one or more leakdetectors or sensors for purposes of monitoring the contents of leakagecollection conduit 112.

FIGS. 9-15 illustrate an alternate embodiment that employs a doublewalled conduit construction. More specifically, FIG. 9 is a perspectiveview of an embodiment of a double walled conduit section 200, FIG. 10 isa perspective view of a detailed portion of conduit section 200; FIG. 11is an end elevation view of the detailed portion of conduit section 200;FIG. 12 is a cross sectional view of two double walled conduit sectionscoupled together; FIG. 13 is a perspective cross sectional view of thetwo conduit sections shown in FIG. 12; FIG. 14 is a perspective view ofthe flange fitting shown in FIGS. 9-11, as viewed from the back side;and FIG. 15 is a perspective face view of the flange fitting depicted atthe right side of FIG. 9. Notably, certain elements, features, andcharacteristics of conduit section 200 are similar or identical tocorresponding elements, features, and characteristics of conduit section100 described above. For the sake of brevity and clarity, such commonaspects will not be redundantly described in the context of conduitsection 200.

Conduit section 200 includes an inner fluid conduit 202 and an outerfluid conduit 204 that surrounds inner fluid conduit 202. This structureis sometimes referred to as a shrouded conduit. Outer fluid conduit 204includes a lumen that is sized to receive inner fluid conduit 202. Innerfluid conduit 202 includes a lumen that allows for a fluid flow (e.g.,gases and liquids) through inner fluid conduit 202. In certainembodiments, outer fluid conduit 204 may be used to concurrently carryanother (or the same) fluid without mixing that fluid with the fluidcontained in inner fluid conduit 202. In other words, the interior spacewithin inner fluid conduit 202 represents one fluid transport conduit,while the space defined between inner fluid conduit 202 and outer fluidconduit 204 represents a second fluid transport conduit. Ideally, andunder nominal operating conditions, these two fluid transport conduitsare fluidly sealed from each other. Inner fluid conduit 202 and outerfluid conduit 204, along with associated support structure, may begenerally constructed in accordance with suitable techniques andtechnologies, such as those described in U.S. Pat. No. 6,848,720 (therelevant content of which is incorporated by reference herein).

Conduit section 200 generally includes, without limitation: a firstflange fitting 206 at one end; a second flange fitting 208 at the otherend; an inner leakage collection conduit 210; and an outer leakagecollection conduit 212. First flange fitting 206 is coupled to (or isintegrally formed with) the first end of conduit section 200 such thatthe opening(s) 214 of inner fluid conduit 202 terminate at first flangefitting 206, and such that the opening(s) 216 of outer fluid conduit 204terminate at first flange fitting 206. In the illustrated embodiment, aweb structure in first flange fitting 206 forms a plurality of openings216 for outer fluid conduit 204. Likewise, second flange fitting 208 iscoupled to (or is integrally formed with) the second end of conduitsection 200 such that the openings of inner fluid conduit 202 and outerfluid conduit 204 terminate at second flange fitting 208.

First flange fitting 206 and second flange fitting 208 are suitablyconfigured to mate with each other such that, when two compatibleconduit sections are coupled together, a fluid tight seal is formedbetween first flange fitting 206 and second flange fitting 208. Ideally,this fluid tight seal prevents the fluid carried by inner fluid conduit202 from leaking into outer fluid conduit 204, and vice versa. For thisparticular embodiment, first flange fitting 206 and second flangefitting 208 are not identical components. Although not a requirement inall embodiments, first flange fitting 206 is designed to be aseal-retaining component, while second flange fitting 208 is designed tobe a seal-cooperating component, as described in more detail below.

FIG. 12 is a side view of a cross section taken through the longitudinalaxis of the conduits, and through an inner leak detection port 230(described below). FIG. 13 is perspective view that combines a crosssection taken through inner leak detection port 230 with a cross sectiontaken through an outer leak detection port 238 (described below). FIG.13 is a cutaway view of the flange fitting assembly that convenientlyshows the configuration of these leak detection ports 230/238. Referringto FIGS. 10, 11, and 14, first flange fitting 206 generally includes aflange body having an inner portion 218 and an outer portion 220, eachhaving a number of features and elements formed therein. The innerportion 218 of the flange body represents one primary section of firstflange fitting 206, and inner portion 218 resides around the opening 214of inner fluid conduit 202. In this embodiment, inner portion 218surrounds and completely encircles the opening 214, as shown in thefigures. The outer portion 220 of the flange body represents anotherprimary section of first flange fitting 206, and outer portion 220resides around the openings 216 associated with outer fluid conduit 204.In this embodiment, outer portion 220 surrounds and completely encirclesthe pattern of openings 216, and surrounds and completely encirclesinner fluid conduit 202, as shown in the figures. The flange bodyincludes a generally defined sealing face surface 222 (see FIG. 12) thatcorresponds to a common plane shared by certain prominent features offirst flange fitting 206. Sealing face surface 222 cooperates and mateswith the respective sealing face surface of the adjoining flangefitting.

The features and elements formed in the outer portion 220 of firstflange fitting 206 include, without limitation: an outermost seal groove224; an outer leak detection passageway 226; an outer intermediate sealgroove 228; and an outer leak detection port 230. The features andelements formed in the inner portion 218 of first flange fitting 206include, without limitation: an inner intermediate seal groove 232; aninner leak detection passageway 234; an innermost seal groove 236; andan inner leak detection port 238. Leak detection ports 230/238 aredepicted in cross section in FIG. 12 and FIG. 13. Due to the cylindricalform of this embodiment of conduit section 200, outermost seal groove224 is a ring shaped channel that encircles the group of openings 216 ofouter fluid conduit 204. For this embodiment, outermost seal groove 224receives and retains an outermost ring seal 240 as depicted in FIG. 12.When deployed in this manner, outermost ring seal 240 remains positionedaround the openings 216 and it runs around the perimeter of first flangefitting 206. Outer intermediate seal groove 228 is similarly configuredto accommodate a seal, sealing compound, a ring seal, a gasket, or thelike. For this embodiment, outer intermediate seal groove 228 receivesand retains an outer intermediate ring seal 242 as shown in FIG. 12.When deployed in this manner, outer intermediate ring seal 242 remainspositioned around the openings 216 and it runs around the perimeter offirst flange fitting 206, and it remains located between outer fluidconduit 204 and outer leak detection passageway 226. Moreover, outermostring seal 240 remains located around outer intermediate ring seal 242.

The design, configuration, and functionality of outermost seal groove224, outermost ring seal 240, outer leak detection passageway 226, outerintermediate seal groove 228, outer intermediate ring seal 242, andouter leak detection port 230 are similar to that described above forfirst flange fitting 108 of conduit section 100. This leak detectionfeature is primarily designed to facilitate the detection of fluidleakage from outer fluid conduit 204. In practice, however, this leakdetection feature can also facilitate the detection of fluid leakagefrom inner fluid conduit 202 (to the extent that fluid also leaks out ofthe outer fluid conduit 204).

Conduit section 200 also includes a leak detection feature for innerfluid conduit 202. Due to the cylindrical form of this embodiment ofconduit section 200, inner intermediate seal groove 232 is a ring shapedchannel that encircles the opening 214 of inner fluid conduit 202. Forthis embodiment, inner intermediate seal groove 232 receives and retainsan inner intermediate ring seal 244 as depicted in FIG. 12. Whendeployed in this manner, inner intermediate ring seal 244 remainspositioned around the opening 214, around inner leak detectionpassageway 234, and around innermost seal groove 236. Innermost sealgroove 236 is similarly configured to accommodate a seal, sealingcompound, a ring seal, a gasket, or the like. For this embodiment,innermost seal groove 236 receives and retains an innermost ring seal246 as shown in FIG. 12. When deployed in this manner, innermost ringseal 246 remains positioned around the opening 214, and it remainslocated between inner fluid conduit 202 and inner leak detectionpassageway 234. Moreover, inner intermediate ring seal 244 remainslocated around innermost ring seal 246.

The design, configuration, and functionality of inner intermediate sealgroove 232, inner intermediate ring seal 244, inner leak detectionpassageway 234, innermost seal groove 236, innermost ring seal 246, andinner leak detection port 238 are similar to that described above forfirst flange fitting 108 of conduit section 100. Inner intermediate ringseal 244 and innermost ring seal 246 are suitably configured andpositioned to nominally seal inner fluid conduit 202 from outer fluidconduit 204 when two cooperating flange fittings are coupled together.Moreover, this leak detection feature facilitates the detection of fluidleakage from outer fluid conduit 204 into inner leak detectionpassageway 234 and/or fluid leakage from inner fluid conduit 202 intoinner leak detection passageway 234.

Outer leak detection port 230 is arranged such that it is in fluidcommunication with outer leak detection passageway 226, and inner leakdetection port 238 is arranged such that it is in fluid communicationwith inner leak detection passageway 234. As described in more detailbelow, leak detection ports 230/238 are suitably configured for fluidcommunication with a leak sensing/detecting apparatus or system.Referring to FIG. 12 and FIG. 13, inner leak detection port 230 providesa fluid path between inner leak detection passageway 234 and the backsurface of the flange body (where the back surface is opposite sealingface surface 222 of the flange body). Notably, inner leak detection port230 is suitably configured to provide a fluid outlet through a bulkportion of flange body. In contrast, outer leak detection port 238 neednot pass through as much material (see, for example, FIG. 5).

FIG. 14 is a perspective view of flange fitting 206, as viewed from itsback side, i.e., the side opposite the front or end side. For clarity,FIG. 14 does not show the fluid conduits that would normally be attachedto flange fitting 206. As described above, leak detection ports 230/238are preferably arranged to be in fluid communication with a leak sensingapparatus or system (not shown). Accordingly, flange fitting 206 mayinclude a first outlet 248 for outer leak detection port 238, and asecond outlet 250 for inner leak detection port 230. First outlet 248 issuitably configured to receive outer leakage collection conduit 212, andsecond outlet 250 is suitably configured to receive inner leakagecollection conduit 210. For this particular embodiment, second outlet250 and inner leak detection port 230 are formed in material thatdefines one of the “spokes” in the web structure of flange fitting 206.This allows inner leak detection port 230 to pass into inner leakdetection passageway 234 while remaining isolated from outer fluidconduit 204. As mentioned above, an appropriate leak detector, sensor,system, or apparatus can be coupled to leakage collection conduits210/212 for purposes of sensing fluid leakage.

Second flange fitting 208 need not be identical to first flange fitting206. For ease of description, FIG. 15 is a perspective face view ofsecond flange fitting 208, shown without the fluid conduits. The backside of second flange fitting 208 is similar to that depicted in FIG.14, and as such it will not be redundantly described here. Second flangefitting 208 includes a flange body 252 (having an outer portion and aninner portion) having a sealing face surface 254 that is configured tomate with a cooperating flange fitting (such as one having thecharacteristics of first flange fitting 206).

Unlike first flange fitting 206, second flange fitting 208 need not haveany seal grooves formed therein. Rather, sealing face surface 254 itselfserves as a cooperating surface that contacts and compresses the sealsof the cooperating flange fitting. FIG. 12 and FIG. 13 illustrate thisfeature. In this embodiment, second flange fitting 208 includes an outerleak detection passageway 256, an outer leak detection port 258, aninner leak detection passageway 260, and an inner leak detection port262 formed therein. Outer leak detection passageway 256 and outer leakdetection port 258 are similar to their respective counterpartsdescribed above for first flange fitting 206. Likewise, inner leakdetection passageway 260 and inner leak detection port 262 are similarto their respective counterparts described above for first flangefitting 206. Notably, each leak detection passageway 256/260 ispreferably shaped, sized, and configured such that it aligns with itsrespective leak detection passageway in the cooperating flange fittingwhen the two flange fittings are connected together (as shown in FIG. 12and FIG. 13). When assembled in this manner, the opposing leak detectionpassageways cooperate and combine to form an inner leak detection ductand an outer leak detection duct.

Referring again to FIG. 12 and FIG. 13, the leak detection ducts aresealed between the sealing face surfaces of the two flange fittings.Moreover, the four ring seals function to nominally isolate the leakdetection ducts from the contents of the fluid conduits. Thus, the leakdetection ducts ideally remain void of the fluid passing through thefluid conduits, absent a leak condition.

Referring back to FIG. 9, leakage collection conduits 210/212 both spanthe length of fluid conduits 202/204 between first flange fitting 206and second flange fitting 208. Thus, one end of inner leakage collectionconduit 210 is coupled to the inner leak detection port of first flangefitting 206, and the other end of inner leakage collection conduit 210is coupled to the inner leak detection port of second flange fitting208. The ends of outer leakage collection conduit 212 are similarlycoupled to flange fittings 206/208. The T-shaped fittings 264 of leakagecollection conduits 210/212 can be utilized as coupling points foradditional conduit, hoses, pipes, or tubes, which in turn can be routedto one or more leak detectors or sensors for purposes of monitoring thecontents of leakage collection conduits 210/212.

FIG. 16 is a schematic representation of an embodiment of a leakdetection system 300 for a dual walled conduit assembly 302. Eachconduit section of assembly 302 may be configured as described above forconduit section 200. FIG. 16 schematically depicts a configuration wherea plurality of inner leakage collection conduits 304 are coupledtogether in series for purposes of monitoring leakage of the inner fluidconduit of assembly 302, and where a plurality of outer leakagecollection conduits 306 are coupled together in series for purposes ofmonitoring leakage of the outer fluid conduit of assembly 302. Thisembodiment of assembly 302 includes an inner leak detector 308 coupledto inner leakage collection conduits 304, and an outer leak detector 310coupled to outer leakage collection conduits 306. Inner leak detector308 is suitably configured to sense fluid leakage into the inner leakdetection passageway(s) located in the flange fittings. Similarly, outerleak detector 310 is suitably configured to sense fluid leakage into theouter leak detection passageway(s) located in the flange fittings.

FIG. 16 depicts a simple deployment where inner leak detector 308 isfluidly coupled to only one of the inner leakage collection conduits304, and where outer leak detector 310 is fluidly coupled to only one ofthe outer leakage collection conduits 306. In practice, however, a givenleak detector can tap into any number of leakage collection conduits.Moreover, a single leak detector may be suitably configured to monitorinner leakage collection conduits 304 and outer leakage collectionconduits 306.

A leak detector 308/310 can be selected, configured, and/or tailored tosuit the needs of the particular application. For example, if themonitored fluid is a gas, then the leak detector may be realized as apressure sensor, a chemical detector, or the like. On the other hand, ifthe monitored fluid is a liquid, then the leak detector may be realizedas a pressure sensor, a volume meter, a flow meter, a liquid receptacle,or the like. If an undesirable amount of leakage is detected by one ofthe leak detectors 308/310, then corrective and/or preventative actioncan be taken as needed. For example, it may be desirable to shut off theflow of fluid through conduit assembly 302, sound an alarm, or the like.

While at least one example embodiment has been presented in theforegoing detailed description, it should be appreciated that a vastnumber of variations exist. It should also be appreciated that theexample embodiment or embodiments described herein are not intended tolimit the scope, applicability, or configuration of the claimed subjectmatter in any way. Rather, the foregoing detailed description willprovide those skilled in the art with a convenient road map forimplementing the described embodiment or embodiments. It should beunderstood that various changes can be made in the function andarrangement of elements without departing from the scope defined by theclaims, which includes known equivalents and foreseeable equivalents atthe time of filing this patent application.

1. A flange fitting for an inner fluid conduit and an outer fluidconduit surrounding the inner fluid conduit, the flange fittingcomprising: a flange body inner portion around an opening of the innerfluid conduit, wherein the flange body inner portion includes an innersealing face surface configured to mate with a cooperating flangefitting; a flange body outer portion around an opening of the outerfluid conduit, wherein the flange body outer portion includes an outersealing face surface configured to mate with the cooperating flangefitting and a back surface opposite the sealing face surface; a spokestructure extending between the flange body inner portion and the flangebody outer portion across the opening for the outer fluid conduit formedbetween the flange body inner portion and the flange body outer portion;an inner leak detection passageway formed in the flange body innerportion, the inner leak detection passageway terminating at the innersealing face surface; and an inner leak detection port formed in theflange body inner portion, the inner leak detection port in fluidcommunication with the inner leak detection passageway and in fluidcommunication with a first outlet on the back surface of the flange bodyouter portion via the spoke structure, and the first outlet beingconfigured for fluid communication with a leak sensing apparatus.
 2. Theflange fitting of claim 1, further comprising a seal configured to sealthe inner leak detection passageway between the inner sealing facesurface and the cooperating flange fitting.
 3. The flange fitting ofclaim 2, wherein the seal is further configured to nominally seal theinner fluid conduit from the outer fluid conduit.
 4. The flange fittingof claim 2, wherein the seal comprises: a first ring seal positionedaround the opening of the inner fluid conduit and located between theinner fluid conduit and the inner leak detection passageway; and asecond ring seal positioned around the opening of the inner fluidconduit and located between the inner leak detection passageway and theouter fluid conduit.
 5. The flange fitting of claim 1, furthercomprising: an outer leak detection passageway formed in the flange bodyouter portion, the outer leak detection passageway terminating at theouter sealing face surface; and an outer leak detection port formed inthe flange body outer portion, the outer leak detection port in fluidcommunication with the outer leak detection passageway and in fluidcommunication with a second outlet on the back surface of the flangebody outer portion, and the second outlet being configured for fluidcommunication with the leak sensing apparatus.
 6. The flange fitting ofclaim 5, further comprising a seal configured to seal the outer leakdetection passageway between the outer sealing face surface and thecooperating flange fitting.
 7. The flange fitting of claim 6, whereinthe seal is further configured to nominally seal the outer leakdetection passageway from the outer fluid conduit.
 8. The flange fittingof claim 6, wherein the seal comprises: a first ring seal positionedaround the opening of the outer fluid conduit and located between theouter fluid conduit and the outer leak detection passageway; and asecond ring seal positioned around the opening of the outer fluidconduit and located around the first ring seal and around the outer leakdetection passageway.
 9. The flange fitting of claim 5, furthercomprising: a first leakage collection conduit coupled to the firstoutlet; a first leak detector coupled to the first leakage collectionconduit, the first leak detector being configured to sense fluid leakageinto the inner leak detection passageway; a second leakage collectionconduit coupled to the second outlet; and a second leak detector coupledto the second leakage collection conduit, the second leak detector beingconfigured to sense fluid leakage into the outer leak detectionpassageway.